A team at Nagoya University in Japan transplanted dental pulp stem cells into rodents with broken backs and discovered the animals regained some leg movement, a breakthrough which could transform the lives of people with spinal cord injuries.

The pulp, found in the centre of the tooth, stopped nerve cells dying, regenerated severed nerves and also encouraged the growth of other cells supporting the spine in the rats, the daily reported.

The dental pulp can be extracted from the centre of adult wisdom teeth "without adverse health effects", according to the scientists.

"There are few ethical concerns regarding their clinical use. We propose that tooth-derived stem cells may be an excellent and practical cellular resource for the treatment of spinal cord injuries," the scientists said. Experts have welcomed the findings. Dr Mark Bacon, research director at the charity Spinal Research, said, "Certainly, within the context of spinal cord injuries, this is a relatively new and under-studied source of stem cells which appears to show remarkably promising result."

Dr Bacon added the scientists' results had been achieved following the immediate transplanting of the cells into the injured area.

He said, "This is not possible in patients, particularly if the cells are to be taken post-injury from the patient and purified. It will therefore be interesting to see how effective these cells are after delayed transplantation."

Added Alex Rankin of spinal injury charity Aspire: "We are excited by the prospect of a cure being found for spinal cord injuries through the use of dental pulp stem cells."